1# SPDX-License-Identifier: GPL-2.0 2 3config EARLY_PRINTK 4 bool "Early printk" if EXPERT 5 depends on SYS_HAS_EARLY_PRINTK 6 default y 7 help 8 This option enables special console drivers which allow the kernel 9 to print messages very early in the bootup process. 10 11 This is useful for kernel debugging when your machine crashes very 12 early before the console code is initialized. For normal operation, 13 it is not recommended because it looks ugly on some machines and 14 doesn't cooperate with an X server. You should normally say N here, 15 unless you want to debug such a crash. 16 17config EARLY_PRINTK_8250 18 bool 19 depends on EARLY_PRINTK && USE_GENERIC_EARLY_PRINTK_8250 20 default y 21 help 22 "8250/16550 and compatible serial early printk driver" 23 If you say Y here, it will be possible to use a 8250/16550 serial 24 port as the boot console. 25 26config USE_GENERIC_EARLY_PRINTK_8250 27 bool 28 29config CMDLINE_BOOL 30 bool "Built-in kernel command line" 31 help 32 For most systems, it is firmware or second stage bootloader that 33 by default specifies the kernel command line options. However, 34 it might be necessary or advantageous to either override the 35 default kernel command line or add a few extra options to it. 36 For such cases, this option allows you to hardcode your own 37 command line options directly into the kernel. For that, you 38 should choose 'Y' here, and fill in the extra boot arguments 39 in CONFIG_CMDLINE. 40 41 The built-in options will be concatenated to the default command 42 line if CMDLINE_OVERRIDE is set to 'N'. Otherwise, the default 43 command line will be ignored and replaced by the built-in string. 44 45 Most MIPS systems will normally expect 'N' here and rely upon 46 the command line from the firmware or the second-stage bootloader. 47 48config CMDLINE 49 string "Default kernel command string" 50 depends on CMDLINE_BOOL 51 help 52 On some platforms, there is currently no way for the boot loader to 53 pass arguments to the kernel. For these platforms, and for the cases 54 when you want to add some extra options to the command line or ignore 55 the default command line, you can supply some command-line options at 56 build time by entering them here. In other cases you can specify 57 kernel args so that you don't have to set them up in board prom 58 initialization routines. 59 60 For more information, see the CMDLINE_BOOL and CMDLINE_OVERRIDE 61 options. 62 63config CMDLINE_OVERRIDE 64 bool "Built-in command line overrides firmware arguments" 65 depends on CMDLINE_BOOL 66 help 67 By setting this option to 'Y' you will have your kernel ignore 68 command line arguments from firmware or second stage bootloader. 69 Instead, the built-in command line will be used exclusively. 70 71 Normally, you will choose 'N' here. 72 73config SB1XXX_CORELIS 74 bool "Corelis Debugger" 75 depends on SIBYTE_SB1xxx_SOC 76 select DEBUG_KERNEL if !COMPILE_TEST 77 select DEBUG_INFO if !COMPILE_TEST 78 help 79 Select compile flags that produce code that can be processed by the 80 Corelis mksym utility and UDB Emulator. 81 82config DEBUG_ZBOOT 83 bool "Enable compressed kernel support debugging" 84 depends on DEBUG_KERNEL && SYS_SUPPORTS_ZBOOT 85 default n 86 help 87 If you want to add compressed kernel support to a new board, and the 88 board supports uart16550 compatible serial port, please select 89 SYS_SUPPORTS_ZBOOT_UART16550 for your board and enable this option to 90 debug it. 91 92 If your board doesn't support uart16550 compatible serial port, you 93 can try to select SYS_SUPPORTS_ZBOOT and use the other methods to 94 debug it. for example, add a new serial port support just as 95 arch/mips/boot/compressed/uart-16550.c does. 96 97 After the compressed kernel support works, please disable this option 98 to reduce the kernel image size and speed up the booting procedure a 99 little. 100 101config ZBOOT_INGENIC_UART 102 int "UART to use for compressed kernel debugging" 103 depends on DEBUG_ZBOOT && MACH_INGENIC_SOC 104 default 0 105 range 0 4 106 help 107 Specify the UART that should be used for compressed kernel debugging. 108 109config SPINLOCK_TEST 110 bool "Enable spinlock timing tests in debugfs" 111 depends on DEBUG_FS 112 default n 113 help 114 Add several files to the debugfs to test spinlock speed. 115 116config SCACHE_DEBUGFS 117 bool "L2 cache debugfs entries" 118 depends on DEBUG_FS 119 help 120 Enable this to allow parts of the L2 cache configuration, such as 121 whether or not prefetching is enabled, to be exposed to userland 122 via debugfs. 123 124 If unsure, say N. 125 126menuconfig MIPS_CPS_NS16550_BOOL 127 bool "CPS SMP NS16550 UART output" 128 depends on MIPS_CPS 129 help 130 Output debug information via an ns16550 compatible UART if exceptions 131 occur early in the boot process of a secondary core. 132 133if MIPS_CPS_NS16550_BOOL 134 135config MIPS_CPS_NS16550 136 def_bool MIPS_CPS_NS16550_BASE != 0 137 138config MIPS_CPS_NS16550_BASE 139 hex "UART Base Address" 140 default 0x1b0003f8 if MIPS_MALTA 141 default 0 142 help 143 The base address of the ns16550 compatible UART on which to output 144 debug information from the early stages of core startup. 145 146 This is only used if non-zero. 147 148config MIPS_CPS_NS16550_SHIFT 149 int "UART Register Shift" 150 default 0 151 help 152 The number of bits to shift ns16550 register indices by in order to 153 form their addresses. That is, log base 2 of the span between 154 adjacent ns16550 registers in the system. 155 156config MIPS_CPS_NS16550_WIDTH 157 int "UART Register Width" 158 default 1 159 help 160 ns16550 registers width. UART registers IO access methods will be 161 selected in accordance with this parameter. By setting it to 1, 2 or 162 4 UART registers will be accessed by means of lb/sb, lh/sh or lw/sw 163 instructions respectively. Any value not from that set activates 164 lb/sb instructions. 165 166endif # MIPS_CPS_NS16550_BOOL 167